Gasoline identification system and method for identifying gasoline type

ABSTRACT

The types of gasolines having different distillation characteristics and various compositions are identified accurately and rapidly. A pulse voltage is applied for a predetermined time to a liquid type identifying sensor heater including a heater and an identifying liquid temperature sensor provided in the vicinity of the heater and an identified gasoline is heated by the heater and the liquid type is identified with a voltage output difference V 0  corresponding to a temperature difference between an initial temperature and a peak temperature in the identifying liquid temperature asensor. Furthermore, a gasoline is introduced between electrodes of an alcohol concentration detecting sensor, and a change in a specific inductive capacity of the gasoline between the electrodes is measured with an oscillation frequency thereby detecting an alcohol concentration in the gasoline. Moreover, based on the alcohol concentration detected by the alcohol concentration detecting device, correcting liquid type identification data in the identification control portion on the basis of alcohol concentration data which are prestored in the identification control portion, thereby identifying a liquid type.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and method for identifyingthe liquid type of a gasoline.

2. Description of Related Art

Conventionally, the exhaust gas of a car contains pollutants such asunburned hydrocarbon (HC), an NOx gas and an SOx gas. In order to reducethe pollutants, therefore, S in a gasoline is removed for the Sox orunburned HC is burned by a catalyst, for example.

More specifically, as shown in FIG. 28, a car system 100 takes air inthrough an automatic element (filter) 102 and feeds the air into anengine 106 through an air flow sensor 104. Moreover, the car system 100feeds a gasoline in a gasoline tank 108 into the engine 106 through agasoline pump 110.

Based on the result of the detection of an A/F sensor 112, the injectionof the fuel in the engine 106 is controlled by a fuel injection controldevice 114 in order to have a predetermined theoretical air fuel ratio.

For an exhaust gas fed from the engine 106, hydrocarbon (HC) in theexhaust gas is burned by a catalytic device 116 and is then dischargedas the exhaust gas through an oxygen concentration sensor 118.

In such a car system, gasolines sold all over the world include variousgasolines having different distillation characteristics (differenteasinesses of evaporation) as shown in FIG. 29.

More specifically, FIG. 29 shows the distillation characteristics ofgasolines, illustrating a relationship between a percentage and atemperature, and an axis of abscissa of 50% (T50) indicates atemperature at which 50% of each gasoline evaporates, for example.

As shown in FIG. 29, for example, a gasoline A2 represents the heaviestgasoline (which rarely evaporates) and a gasoline No. 7 represents thelightest gasoline (which easily evaporates) with respect to a standardgasoline No. 3.

As shown in the following Table 1, accordingly, in the case in which theheavier gasoline A2 is used in a car regulated to have a theoretical airfuel ratio with the standard gasoline No. 3, for example, the amount ofHC in an exhaust gas is small and a torque becomes insufficient,particularly, at time of engine starting in which an engine and acatalytic device do not warm up.

To the contrary, in the case in which the lighter gasoline No. 7 isused, the torque is insufficient and the theoretical air fuel ratio isexceeded. As a result, the amount of the HC in the exhaust gas isincreased, particularly, at time of the engine starting in which theengine and the catalytic device do not warm up, which is not preferablebecause an environment is greatly influenced.

TABLE 1 Regulated Used Exhaust gas gasoline gasoline Torque (HC) No. 3No. 3 ◯ ◯ No. 3 A2 X ◯ No. 3 No. 7 ◯ X

The present inventors have proposed a fluid identifying method inJapanese Laid-Open Patent Publication No. Hei 11(1999)-153561(particularly see paragraphs (0042) to (0049)) (which will behereinafter referred to as “Patent Document 1”). In this method, aheating member is caused to generate heat by carrying electricity, atemperature detector is heated through the heat generation, a heattransfer from the heating member to the temperature detector isthermally influenced through a fluid to be identified, and the type ofthe identified fluid is distinguished based on an electrical outputcorresponding to the electric resistance of the temperature detector. Inthis method, the electricity is periodically carried to the heatingmember.

In the fluid identifying method, however, it is necessary toperiodically carry the electricity to the heating member (in amultipulse). For this reason, a long time is required for theidentification so that it is hard to identify a fluid instantaneously.In this method, moreover, it is possible to identify a fluid based on acentral value for substances having very different characteristics suchas water, air and oil. However, it is hard to identify the gasolineshaving very close characteristics to each other accurately and rapidly.

Conventionally, a so-called high-octane gasoline having an octane valueincreased such as lead or a benzene based compound, or a gasoline intowhich an antiknocking agent such as methyl tertiary butyl ether ormethyl-t-butyl ether (MTBE) is mixed has been used for a car or the likein order to prevent knocking, for example.

However, there is a possibility that the lead, the benzene basedcompound or the like might influence an environment. Moreover, it issaid that the methyl tertiary butyl ether or the methyl-t-butyl ether(MTBE) is cancer-causing. For this reason, it has been desired todevelop the high-octane gasoline and an antiknocking agent in place ofthe antiknocking agent constituted by the methyl tertiary butyl ether orthe methyl-t-butyl ether (MTBE).

Therefore, it has been proposed that alcohol, for example, ethanol isadded, as the antiknocking agent, in an amount of approximately 10 to15% to a gasoline.

However, such ethanol is added so that a torque is reduced. Therefore,it is necessary to cause the torque to be constant by excessively addinga gasoline corresponding to the amount of addition of the ethanol.

In the case in which the alcohol is contained in the gasoline in theidentification of the liquid type of the gasoline as described above,furthermore, liquid type identification data are influenced. As aresult, it is hard to identify the liquid type accurately and rapidly.

For this reason, it has been desired to detect the concentration ofalcohol contained in a gasoline.

As a method for detecting the concentration of alcohol, conventionally,an optical alcohol concentration measuring apparatus for detecting theconcentration of alcohol by utilizing the refractive index of a lighthas been disclosed as in Japanese Laid-Open Patent Publication No. Hei 5(1993)-223733 (see paragraphs (0017) to (0030) and FIG. 1)(whichwillbehereinafter referred to as “Patent Document 2”).

More specifically, in an optical alcohol concentration measuringapparatus 200 in the Patent Document 2, as shown in FIG. 30, a lightwhich is transmitted from a first light emitting portion 202 through aliquid and has a wavelength with such a property that an absorption intoalcohol such as ethanol is hard to perform is received by a first lightreceiving portion 204 and a detection signal corresponding to an alcoholconcentration in the liquid is output.

Moreover, a light, which is transmitted from a second light emittingportion 206 through the liquid and has another wavelength with such aproperty that the absorption into the alcohol is easy, is received by asecond light receiving portion 208 and a detection signal correspondingto the alcohol concentration in the liquid is output.

Consequently, in a measuring portion 210, the detection signal sent fromthe first light receiving portion 204 is compared with the detectionsignal sent from the second light receiving portion 208 and the alcoholconcentration in the liquid is measured.

As described in “Electrostatic Capacitance Type Alcohol ConcentrationSensor” (see Norio Sanma, Ikuo Hayashi, Ichiro Hosotani, The Society ofAutomotive Engineers of Japan, Annual Congress Preliminary PrintingCollection 936, 1993-10, pages 257 to 260) (which will be herein afterreferred to as “Non-Patent Document 1”), conventionally, anelectrostatic capacitance type alcohol concentration sensor has beenproposed.

In the Non-Patent Document 1, there has been proposed a method formeasuring the concentration of methanol mixed into a gasoline from anelectrostatic capacitance between electrodes at an oscillation frequencyby utilizing a difference in a specific inductive capacity between thegasoline and the methanol (the gasoline has a specific inductivecapacity of 2 and the methanol has a specific inductive capacity of33.6), thereby detecting the concentration of the methanol.

An electrostatic capacitance type alcohol concentration sensor 300according to the Non-Patent Document 1 has such a structure that anouter electrode 304 and a center electrode 306 are attached through aninsulating resin 308 into a housing 302 as shown in FIG. 31.

Since the optical alcohol concentration measuring apparatus according tothe Patent Document 2 utilizes a transmitted light, however, it iseasily influenced by the composition of a gasoline. For example, in thecase in which the gasoline is not transparent due to an impurity,moreover, a measurement cannot be carried out or an accurate measurementcannot be performed.

In the electrostatic capacitance type alcohol concentration sensorutilizing an electrostatic capacitance according to the Non-PatentDocument 1, furthermore, a moisture is apt to enter alcohol and a shortcircuit is generated between electrodes if the moisture, an electrolyteor the like is present between the electrodes. Accordingly, aninsulating treatment for the surface of the electrode is required and astructure thereof is complicated.

In this case, an electrostatic capacitance C_(s) is expressed in thefollowing equation.C _(s)=ε₀(S/D) (ε ra(α/100)+εrg(1−α/100))  Equation 1

Herein, S represents an opposed area of an electrode, D represents adistance between the electrodes, ε₀ represents a specific inductivecapacity of a vacuum (8.854 E−12 F/m), ε ra represents a specificinductive capacity of alcohol, ε rg represents a specific inductivecapacity of a gasoline, and a represents an alcohol concentration (%).

As is apparent from the Equation, accordingly, it is preferable toincrease the opposed area of the electrode to increase the electrostaticcapacitance Cs in order to obtain the excellent results of themeasurement. When the opposed area of the electrode is thus increased,however, the size of the electrostatic capacitance type alcoholconcentration sensor itself is increased as in the Non-PatentDocument 1. For this reason, handling, an application to a car and thelike are also restricted in respect of a design.

In the electrostatic capacitance type alcohol concentration sensoraccording to the Non-Patent Document 1, furthermore, the sensor is to beconnected to a body of a gasoline piping in a car or the like, forexample. However, a noise such as an electromagnetic wave or the likewhich is generated from the body influences an alcohol-concentrationdetecting circuit so that an accurate measurement cannot be carried out.

For this reason, an insulating structure is added to the connectingportion of the sensor and the piping or the whole large-sized sensor isto be put in an insulating shield container. Consequently, the apparatusbecomes complicated and large-sized.

In consideration of such circumstances, it is an object of the presentinvention to provide an apparatus and method for identifying the liquidtype of a gasoline which can identify the type of a gasoline accuratelyand rapidly by detecting an alcohol concentration in each of gasolineshaving different distillation characteristics and various compositionsand correcting liquid type identification data on the gasolines based ona result.

Moreover, it is an object of the present invention to provide anapparatus for identifying the liquid type of a gasoline, comprising analcohol concentration detecting device which is small-sized and compact,can be installed everywhere and can have the degree of freedom of adesign, has an excellent insulation between electrodes and is notinfluenced by a moisture, can carry out shielding in order not to beinfluenced by an electromagnetic wave generated from a body of a car orthe like, and furthermore, can execute an accurate measurement for thealcohol concentration, and a method for identifying the liquid type of agasoline.

Furthermore, it is an object of the present invention to provide anapparatus and method for identifying the liquid type of the gasoline ofa car using the apparatus and method for identifying the liquid type ofa gasoline.

In addition, it is an object of the present invention to provide anapparatus and method for reducing the exhaust gas of a car using theapparatus and method for identifying the liquid type of a gasoline whichcan efficiently reduce the exhaust gas and can enhance a mileage.

SUMMARY OF THE INVENTION

The present invention has been made to solve the problems of the priorart and to attain the objects described above, and provides an apparatusfor identifying a liquid type of a gasoline, comprising:

a gasoline liquid type identifying chamber for causing an identifiedgasoline introduced into the liquid type identifying apparatus body tostay temporarily;

a liquid type identifying sensor heater provided in the gasoline liquidtype identifying chamber; and

a liquid temperature sensor provided in the gasoline liquid typeidentifying chamber apart from the liquid type identifying sensor heaterat a constant interval;

the liquid type identifying sensor heater including a heater and anidentifying liquid temperature sensor provided in the vicinity of theheater,

the apparatus further comprising an identification control portion forapplying a pulse voltage to the liquid type identifying sensor heaterfor a predetermined time, heating the identified gasoline stayingtemporarily in the gasoline liquid type identifying chamber by theheater and identifying the liquid type with a voltage output differenceV0 corresponding to a temperature difference between an initialtemperature and a peak temperature in the identifying liquid temperaturesensor, and

an alcohol content detecting chamber,

the alcohol content detecting chamber being provided with an alcoholconcentration detecting device in which an alcohol concentration in thegasoline is detected by introducing a gasoline between electrodes of analcohol concentration detecting sensor and by measuring a change in aspecific inductive capacity of the gasoline between the electrodes withan oscillation frequency,

wherein based on the alcohol concentration detected by the alcoholconcentration detecting device, liquid type identification data in theidentification control portion being corrected on the basis of alcoholconcentration data which are prestored in the identification controlportion, thereby identifying a liquid type.

Moreover, the present invention provides a method for identifying aliquid type of a gasoline, comprising the steps of:

applying a pulse voltage for a predetermined time to a liquid typeidentifying sensor heater including a heater and an identifying liquidtemperature sensor provided in the vicinity of the heater, heating anidentified gasoline by the heater, and identifying the liquid type witha voltage output difference V0 corresponding to a temperature differencebetween an initial temperature and a peak temperature in the identifyingliquid temperature sensor;

introducing a gasoline between electrodes of an alcohol concentrationdetecting sensor, and measuring a change in a specific inductivecapacity of the gasoline between the electrodes with an oscillationfrequency thereby detecting an alcohol concentration in the gasoline;and

based on the alcohol concentration detected by the alcohol concentrationdetecting device, correcting liquid type identification data in theidentification control portion on the basis of alcohol concentrationdata which are prestored in the identification control portion, therebyidentifying a liquid type.

By such a structure, it is sufficient that the pulse voltage is appliedfor the predetermined time. Consequently, it is possible to identify thetype of a gasoline accurately and rapidly through heating for a shorttime without carrying out the heating to such a temperature as to ignitethe gasoline.

More specifically, there are utilized the correlation of the kineticviscosity of the gasoline with a sensor output, a natural convection,and furthermore, an applied voltage having one pulse. Therefore, it ispossible to identify the type of the gasoline accurately and rapidly.

In addition, it is possible to detect an alcohol concentration in thegasoline and to correct liquid type identification data on the gasolinebased on a result, thereby identifying the type of the gasolineaccurately and rapidly.

Furthermore, the present invention is characterized in that the voltageoutput difference V0 is equal to a voltage difference between an averageinitial voltage V1 obtained by sampling an initial voltage beforeapplication of the pulse voltage at a predetermined number of times andan average peak voltage V2 obtained by sampling a peak voltage after theapplication of the pulse voltage at a predetermined number of times,that is,V0=V2−V1.

By such a structure, it is possible to accurately obtain the voltageoutput difference V0 based on the average value of the sampling at thepredetermined number of times for the applied voltage having one pulse.Consequently, it is possible to identify the type of a gasolineaccurately and rapidly.

Moreover, the apparatus for identifying a liquid type of a gasolineaccording to the present invention is characterized in that, inaccordance with calibration curve data to be a correlation of a voltageoutput difference with a temperature for a predetermined referencegasoline prestored in the identification control portion, theidentification control portion is constituted to identify a type of agasoline with the voltage output difference V0 obtained for theidentified gasoline.

In addition, the method for identifying a liquid type of a gasolineaccording to the present invention is characterized in that, inaccordance with calibration curve data to be a correlation of a voltageoutput difference with a temperature for a predetermined referencegasoline which is prestored, a type of a gasoline is identified with thevoltage output difference V0 obtained for the identified gasoline.

By such a structure, in accordance with the calibration curve data to bethe correlation of the voltage output difference with the temperaturefor the predetermined reference gasoline which is prestored, the type ofthe gasoline is identified with the voltage output difference V0obtained for the identified gasoline. Therefore, it is possible toidentify the type of the gasoline more accurately and rapidly.

Furthermore, the apparatus for identifying a liquid type of a gasolineaccording to the present invention is characterized in that theidentification control portion is constituted to correlate a liquid typevoltage output Vout for the voltage output difference V0 at a measuringtemperature of the identified gasoline with an output voltage for avoltage output difference at a measuring temperature for a predeterminedthreshold reference gasoline and to thus carry out a correction.

Moreover, the method for identifying a liquid type of a gasolineaccording to the present invention is characterized in that a liquidtype voltage output Vout for the voltage output difference V0 at ameasuring temperature of the identified gasoline is correlated with anoutput voltage for a voltage output difference at a measuringtemperature for a predetermined threshold reference gasoline and is thuscorrected.

By such a structure, the liquid type voltage output Vout for the voltageoutput difference V0 at the measuring temperature of the identifiedgasoline is correlated with the output voltage for the voltage outputdifference at the measuring temperature for the predetermined thresholdreference gasoline and is thus corrected. Consequently, it is possibleto eliminate the influence of the temperature on the voltage outputdifference V0, thereby giving the correlation of the liquid type voltageoutput Vout with the characteristics of the gasoline more accurately.Thus, it is possible to identify the type of the gasoline furtheraccurately and rapidly.

Furthermore, the present invention is characterized in that the liquidtype identifying sensor heater is a laminated liquid type identifyingsensor heater in which a heater and an identifying liquid temperaturesensor are laminated through an insulating layer.

By such a structure, a mechanism portion for carrying out a mechanicaloperation is not present. Therefore, a defective operation can beprevented from being caused by a deterioration with the passage of time,foreign matters in the gasoline or the like. Thus, it is possible toidentify the liquid type of the gasoline accurately and rapidly.

In addition, the sensor portion can be constituted to be verysmall-sized. Consequently, it is possible to identify the liquid type ofthe gasoline accurately with a very excellent thermal responsiveness.

Moreover, the present invention is characterized in that the heater andthe identifying liquid temperature sensor in the liquid type identifyingsensor heater are constituted to come in contact with the identifiedgasoline through a metallic fin, respectively.

By such a structure, the heater and the identifying liquid temperaturesensor in the liquid type identifying sensor heater do not directly comein contact with the identified gasoline. Therefore, a defectiveoperation can be prevented from being caused by a deterioration with thepassage of time, foreign matters in the gasoline or the like. Thus, itis possible to identify the liquid type of the gasoline accurately andrapidly.

Furthermore, the present invention is characterized in that the liquidtemperature sensor is constituted to come in contact with the identifiedgasoline through the metallic fin.

By such a structure, the liquid temperature sensor does not directlycome in contact with the identified gasoline. Therefore, a defectiveoperation can be prevented from being caused by a deterioration with thepassage of time, foreign matters in the gasoline or the like. Thus, itis possible to identify the liquid type of the gasoline accurately andrapidly.

Moreover, the present invention is characterized in that the alcoholconcentration detecting sensor comprises an alcohol concentrationdetecting sensor body including a base material resin film, an electrodewiring pattern formed on the base material resin film, and an insulatingresin covering a surface of the electrode wiring pattern.

By such a structure, it is possible to reduce a distance between theelectrodes by using the electrode wiring pattern formed on the basematerial resin film. As is apparent from Equation 2 which will bedescribed below, therefore, an electrostatic capacitance C_(s) can beincreased so that the excellent result of the measurement can beobtained.

In addition, the alcohol concentration detecting sensor is constitutedby the base material resin film, the electrode wiring pattern formed onthe base material resin film, and the insulating resin covering thesurface of the electrode wiring pattern. Therefore, the sensor itself isflexible, thin, very small and compact, and can be installed everywhereso that the degree of freedom of a design can be increased.

Furthermore, the surface of the electrode wiring pattern is covered withthe insulating resin. Therefore, an insulation between the electrodes isexcellent and is not influenced by a moisture, and shielding can becarried out in order to prevent the influence of an electromagnetic wavegenerated from the body of a car or the like. Furthermore, an accuratemeasurement for the alcohol concentration can be executed.

Moreover, the electrode does not directly come in contact with thegasoline. Therefore, a defective operation can be prevented from beingcaused by a deterioration with the passage of time, foreign matters inthe gasoline or the like. Thus, it is possible to detect the alcoholconcentration accurately and rapidly.

In addition, the present invention is characterized in that the alcoholconcentration detecting sensor body is stuck onto a substrate.

By such a structure, the alcohol concentration detecting sensor body isstuck onto the substrate. Therefore, it is easy to assemble and attachthe alcohol concentration detecting sensor body into the apparatus.

Moreover, the present invention is characterized in that the electrodewiring pattern is obtained by selectively etching a conductive metallicfoil laminated on one of surfaces of the base material resin film,thereby forming a wiring pattern taking a predetermined shape.

By such a structure, it is possible to obtain an electrode wiringpattern having a very small distance between the electrodes, forexample, within a range of approximately 5 μm to 50 μm by etching.Therefore, the electrostatic capacitance C_(s) can be increased so thatthe excellent result of the measurement can be obtained.

In addition, the sensor itself is thin, very small and compact, and canbe installed everywhere so that the degree of freedom of a design can beincreased.

Furthermore, the present invention is characterized in that the alcoholconcentration detecting sensor comprises a substrate, an electrodewiring pattern formed on the substrate, and an insulating coat coveringa surface of the electrode wiring pattern.

By such a structure, it is possible to reduce a distance between theelectrodes by using the electrode wiring pattern formed on thesubstrate. As is apparent from the Equation 2 which will be describedbelow, therefore, an electrostatic capacitance C_(s) can be increased sothat the excellent result of the measurement can be obtained.

In addition, the alcohol concentration detecting sensor is constitutedby the substrate, the electrode wiring pattern formed on the substrate,and the insulating coat covering the surface of the electrode wiringpattern. Therefore, the sensor itself is thin, very small and compact,and can be installed everywhere so that the degree of freedom of adesign can be increased.

Furthermore, the surface of the electrode wiring pattern is covered withthe insulating coat. Therefore, an insulation between the electrodes isexcellent and is not influenced by a moisture, and shielding can becarried out in order to prevent the influence of an electromagnetic wavegenerated from the body of a car or the like. Furthermore, an accuratemeasurement for the alcohol concentration can be executed.

Moreover, the electrode does not directly come in contact with thegasoline. Therefore, a defective operation can be prevented from beingcaused by a deterioration with the passage of time, foreign matters inthe gasoline or the like. Thus, it is possible to detect the alcoholconcentration accurately and rapidly.

In addition, the substrate is provided. Therefore, it is easy toassemble and attach the alcohol concentration detecting sensor into theapparatus.

Moreover, the present invention is characterized in that the electrodewiring pattern is obtained by selectively etching a conductive metallicthin film formed on one of surfaces of the substrate by sputtering,thereby forming a wiring pattern taking a predetermined shape.

By such a structure, it is possible to obtain an electrode wiringpattern having a thickness of 0.1 to 5 μm by sputtering at a very smalldistance between the electrodes, for example, within a range ofapproximately 5 μm to 50 μm by the sputtering. Therefore, theelectrostatic capacitance CS can be increased so that the excellentresult of the measurement can be obtained.

In addition, the sensor itself is thin, very small and compact, and canbe installed everywhere so that the degree of freedom of a design can beincreased.

Furthermore, the present invention is characterized in that theinsulating coat is formed by chemical vapor deposition (CVD).

By such a structure, it is possible to obtain, by the chemical vapordeposition (CVD), a very minute and thin insulating coat such as SiO₂,Al₂O₃ and the like, which is not influenced by the liquid to beinspected such as a gasoline or alcohol. Thus, the sensor itself can bethin, very small and compact.

Moreover, the present invention is characterized in that the electrodewiring pattern has such a shape that positive and negative electrodeswhich are comb-toothed are alternately intricate.

By such a structure, the positive and negative electrodes which arecomb-toothed are formed to be alternately intricate. Therefore, theelectrodes having a very small distance therebetween can be provided tobe compact as a whole.

Accordingly, it is possible to obtain an electrode wiring pattern havinga very small distance between the electrodes, for example, within arange of approximately 5 μm to 50 μm by etching and sputtering,respectively. Therefore, the electrostatic capacitance C_(s) can beincreased so that the excellent result of the measurement can beobtained.

In addition, the sensor itself is thinner, much smaller and morecompact, and can be installed everywhere so that the degree of freedomof a design can be increased.

Furthermore, the present invention provides an apparatus for identifyinga liquid type of a gasoline of a car, wherein any of the apparatuses foridentifying a liquid type of a gasoline is provided in a gasoline tankor on an upstream side or a downstream side of a gasoline pump.

In addition, the present invention provides a method for identifying aliquid type of a gasoline of a car, comprising the step of:

identifying a type of a gasoline in a gasoline tank or on an upstreamside or a downstream side of a gasoline pump by using any of the methodsfor identifying a liquid type of a gasoline.

By such a structure, it is possible to identify the type of a gasolineaccurately and rapidly in a car.

Moreover, the present invention provides an apparatus for reducing anexhaust gas of a car, comprising:

any of the apparatuses for identifying a liquid type of a gasoline whichis provided in a gasoline tank or on an upstream side or a downstreamside of a gasoline pump; and

an ignition timing control device for regulating an ignition timingbased on the type of the gasoline which is identified by the apparatusfor identifying a liquid type of a gasoline.

Furthermore, the present invention provides a method for reducing anexhaust gas of a car, comprising the steps of:

identifying a type of a gasoline in a gasoline tank or on an upstreamside or a downstream side of a gasoline pump by using any of the methodsfor identifying a liquid type of a gasoline, and

regulating an ignition timing based on the type of the gasoline which isidentified by the apparatus for identifying a liquid type of a gasoline.

By such a structure, an ignition timing can be regulated based on theresult of the identification of the type of the gasoline. Therefore, itis possible to obtain a proper ignition timing corresponding to the typeof the gasoline.

Accordingly, it is also possible to reduce the amount of HC in anexhaust gas and to enhance a mileage without decreasing a torque,particularly, at time of engine starting in which an engine and acatalytic device do not warm up.

Moreover, the present invention provides an apparatus for reducing anexhaust gas of a car, comprising:

any of the apparatuses for identifying a liquid type of a gasoline whichis provided in a gasoline tank or on an upstream side or a downstreamside of a gasoline pump; and

a gasoline compression control device for regulating a compressibilityof the gasoline based on the type of the gasoline which is identified bythe apparatus for identifying a liquid type of a gasoline.

In addition, the present invention provides a method for reducing anexhaust gas of a car, comprising the steps of:

identifying a type of a gasoline in a gasoline tank or on an upstreamside or a downstream side of a gasoline pump by using any of the methodsfor identifying a liquid type of a gasoline; and

regulating a compressibility of the gasoline based on the type of thegasoline which is identified by the apparatus for identifying a liquidtype of a gasoline.

By such a structure, the compressibility of the gasoline can beregulated based on the result of the identification of the type of thegasoline. Therefore, it is possible to obtain a proper compressibilityof the gasoline corresponding to the type of the gasoline.

Accordingly, it is also possible to reduce the amount of HC in anexhaust gas and to enhance a mileage without decreasing a torque,particularly, at time of engine starting in which an engine and acatalytic device do not warm up.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic top view showing an example of an apparatus foridentifying the liquid type of a gasoline according to the presentinvention.

FIG. 2 is a sectional view taken along an A—A line in FIG. 1.

FIG. 3 is a right side view of FIG. 1.

FIG. 4 is a left side view of FIG. 1.

FIG. 5 is a partially enlarged sectional view showing a state in which aliquid type identifying sensor is attached in FIG. 2.

FIG. 6 is a sectional view showing the liquid type identifying sensor.

FIG. 7 is a partially enlarged exploded perspective view showing a statein which the thin film chip portions of the liquid type identifyingsensor are laminated.

FIG. 8 is a schematic diagram showing the structure of a circuitaccording to the example of the apparatus for identifying the liquidtype of a gasoline according to the present invention.

FIG. 9 is a graph showing a relationship between a time and a voltage,illustrating a method for identifying a liquid type using the apparatusfor identifying the liquid type of a gasoline according to the presentinvention.

FIG. 10 is a graph showing a calibration curve, illustrating the methodfor identifying a liquid type using the apparatus for identifying theliquid type of a gasoline according to the present invention.

FIG. 11 is a graph showing an output correcting method in the method foridentifying a liquid type using the apparatus for identifying the liquidtype of a gasoline according to the present invention.

FIG. 12 is a graph showing a relationship between the concentration ofalcohol and an electrostatic capacitance.

FIG. 13 is a schematic circuit diagram showing the structure of analcohol concentration detecting device according to the presentinvention.

FIG. 14 is a schematic diagram showing a square-wave voltage to beapplied by the alcohol concentration detecting device according to thepresent invention.

FIG. 15 is a graph showing a relationship between an alcoholconcentration and an oscillation frequency.

FIG. 16 is a schematic perspective view showing an example of an alcoholconcentration detecting sensor in the alcohol concentration detectingdevice according to the present invention.

FIG. 17 is a schematic top view showing an electrode wiring pattern inFIG. 16.

FIG. 18 is an enlarged view showing a B portion in FIG. 17.

FIG. 19 is a partially enlarged sectional view taken along a C—C line inFIG. 16.

FIG. 20 is a schematic view showing a method for manufacturing thealcohol concentration detecting sensor in the alcohol concentrationdetecting device according to the present invention.

FIG. 21 is a schematic perspective view showing another example of thealcohol concentration detecting sensor in the alcohol concentrationdetecting device according to the present invention.

FIG. 22 is a schematic top view showing an electrode wiring pattern inFIG. 21.

FIG. 23 is an enlarged view showing a B portion in FIG. 22.

FIG. 24 is a partially enlarged sectional view taken along a C—C line inFIG. 21.

FIG. 25 is a schematic view showing a method for manufacturing thealcohol concentration detecting sensor in the alcohol concentrationdetecting device according to the present invention.

FIG. 26 is the same schematic diagram as FIG. 28, illustrating anexample in which an apparatus 10 for identifying the liquid type of agasoline according to the present invention is applied to a car system.

FIG. 27 is the same schematic diagram as FIG. 28, illustrating anexample in which the apparatus 10 for identifying the liquid type of agasoline according to the present invention is applied to the carsystem.

FIG. 28 is a schematic diagram showing a conventional car system.

FIG. 29 is a graph showing the distillation characteristics of agasoline.

FIG. 30 is a schematic view showing a conventional optical alcoholconcentration measuring apparatus.

FIG. 31 is a sectional view showing a conventional electrostaticcapacitance type alcohol concentration sensor.

BEST MODE FOR CARRYING OUT DETAILED DESCRIPTION OF THE INVENTION

Embodiments (examples) of the present invention will be described belowin more detail with reference to the drawings.

FIG. 1 is a schematic top view showing an example of an apparatus foridentifying the liquid type of a gasoline according to the presentinvention, FIG. 2 is a sectional view taken along an A—A line in FIG. 1,FIG. 3 is a right side view of FIG. 1, FIG. 4 is a left side view ofFIG. 1, FIG. 5 is a partially enlarged sectional view showing a state inwhich a liquid type identifying sensor is attached in FIG. 2, FIG. 6 isa sectional view showing the liquid type identifying sensor, FIG. 7 is apartially enlarged exploded perspective view showing a state in whichthe thin film chip portions of the liquid type identifying sensor arelaminated, FIG. 8 is a schematic diagram showing the structure of acircuit according to the example of the apparatus for identifying theliquid type of a gasoline according to the present invention, FIG. 9 isa graph showing a relationship between a time and a voltage,illustrating a method for identifying a liquid type using the apparatusfor identifying the liquid type of a gasoline according to the presentinvention, FIG. 10 is a graph showing a calibration curve, illustratingthe method for identifying a liquid type using the apparatus foridentifying the liquid type of a gasoline according to the presentinvention, and FIG. 11 is a graph showing an output correcting method inthe method for identifying a liquid type using the apparatus foridentifying the liquid type of a gasoline according to the presentinvention.

As shown in FIGS. 1 and 2, an apparatus 10 for identifying the liquidtype of a gasoline according to the present invention comprises a liquidtype identifying apparatus body 12, and a first passage 14 and a secondpassage 16 which are formed in the liquid type identifying apparatusbody 12.

As shown in an arrow of FIG. 1, a gasoline to be identified which flowsfrom a gasoline inlet 18 into the first passage 14 passes through analcohol content detecting chamber 56. Then, the identified gasolinepasses through the alcohol content detecting chamber 56, and thereafter,enters the second passage 16 to temporarily stay in a gasoline liquidtype identifying chamber 20. The gasoline liquid type identifyingchamber 20 is provided with an opening portion 22 for a liquid typeidentifying sensor taking the shape of an almost truck in an upper partthereof.

As shown in FIG. 2, a liquid type identifying sensor 24 is attached tothe opening portion 22 for the liquid type identifying sensor.

As shown in FIG. 5, the liquid type identifying sensor 24 includes aliquid type identifying sensor heater 25 and a liquid temperature sensor28 provided apart from the liquid type identifying sensor heater 25 at aconstant interval. The liquid type identifying sensor heater 25 and theliquid temperature sensor 28 are formed integrally by a mold resin 30.

As shown in FIG. 6, moreover, the liquid type identifying sensor heater25 includes a lead electrode 32 and a thin film chip portion 34.Moreover, the liquid type identifying sensor heater 25 is provided witha metallic fin 36 which is protruded into the gasoline liquid typeidentifying chamber 20 through the opening portion 22 for the liquidtype identifying sensor from the mold resin 30 and which comes intodirect in contact with the identified gasoline. The lead electrode 32,the thin film chip portion 34 and the fin 36 are mutually connectedelectrically through a bonding wire 38.

On the other hand, the liquid temperature sensor 28 also has the samestructure as that of the liquid type identifying sensor heater 25, andincludes the lead electrode 32, the thin film chip portion 34, the fin36 and the bonding wire 38 respectively.

As shown in FIG. 7, the thin film chip portion 34 is constituted by athin film-shaped chip in which a substrate 40 formed of Al₂O₃, atemperature sensor (temperature detector) 42 formed of PT, an interlayerinsulating film 44 formed of SiO₂, a heater (heating member) 46 formedof TaSiO₂, a heating member electrode 48 formed of Ni, a protective film50 formed of SiO₂, and an electrode pad 52 formed of Ti/Au are providedin order, for example.

While the thin film chip portion 34 of the liquid temperature sensor 28also has the same structure, it is so constituted as not to cause theheater (heating member) 46 to act but to cause only the temperaturesensor (temperature detector) 42 to act.

After the liquid type of the identified gasoline is identified by theliquid type identifying sensor 24, the identified gasoline is dischargedfrom the gasoline liquid type identifying chamber 20 to an outsidethrough a gasoline discharge port 54.

On the other hand, the identified gasoline flowing into the firstpassage 14 through the gasoline inlet 18 then stays temporarily in thealcohol content detecting chamber 56. In this state, when the gasolinecontains the alcohol, the concentration of alcohol is detected by analcohol detecting sensor 58. Thereafter, the same gasoline is dischargedfrom the alcohol content detecting chamber 56 through the gasolinedischarge port 54 of the second passage 16. The details of the detectionof the alcohol concentration will be described below.

In FIGS. 1 and 2, moreover, circuit board members connected to theliquid type identifying sensor 24 and the alcohol detecting sensor 58and lid members for covering them are not shown.

The apparatus 10 for identifying the liquid type of a gasoline accordingto the present invention has the structure of a circuit shown in FIG. 8.

In FIG. 8, an identifying liquid temperature sensor 26 of the liquidtype identifying sensor heater 25 and the liquid temperature sensor 28in the liquid type identifying sensor 24 are connected to each otherthrough two resistors 64 and 66, thereby constituting a bridge circuit68. The output of the bridge circuit 68 is connected to the input of anamplifier 70, and the output of the amplifier 70 is connected to theinput of a computer 72 constituting an identification control portion.

Moreover, the applied voltage of a heater 74 of the liquid typeidentifying sensor heater 25 is controlled under the control of thecomputer 72.

In the apparatus 10 for identifying the liquid type of a gasoline whichhas such a structure, the liquid type of the gasoline is identified inthe following manner.

First of all, the identified gasoline is caused to flow from thegasoline inlet 18 of the first passage 14 of the apparatus 10 foridentifying the liquid type of a gasoline and is caused to staytemporarily in the gasoline liquid type identifying chamber 20 of thesecond passage 16.

As shown in FIGS. 8 and 9, a pulse voltage P is applied to the heater 74of the liquid type identifying sensor heater 25 under the control of thecomputer 72 for a predetermined time, that is, four seconds in thepresent example. Thereafter, a change in the temperature of the analogoutput of a sensing portion, that is, the sensor bridge circuit 68 shownin FIG. 8 is measured.

More specifically, as shown in FIG. 9, the voltage difference of thesensor bridge circuit 68 is sampled at a predetermined number of times,for example, 256 times in the present example for one second before thepulse voltage P is applied to the heater 74 of the liquid typeidentifying sensor heater 25. As a result, an average value thereof isset to be an average initial voltage V1. The value of the averageinitial voltage V1 corresponds to the initial temperature of theidentifying liquid temperature sensor 26.

As shown in FIG. 9, the predetermined pulse voltage P, that is, avoltage of 10V in the present example is applied to the heater 74 of theliquid type identifying sensor heater 25 for four seconds. Subsequently,a value obtained by sampling a peak voltage at a predetermined number oftimes, for example, 256 times in the present example for one secondafter a predetermined time, for example, 3 seconds in the presentexample is set to be an average peak voltage V2. The average peakvoltage V2 corresponds to the peak temperature of the identifying liquidtemperature sensor 26.

A voltage output difference V0 is obtained from a voltage differencebetween the average initial voltage V1 and the average peak voltage V2,that is,V0=V2−V1.

By such a method, as shown in FIG. 10, calibration curve data to be thecorrelation of a voltage output difference with a temperature arepreviously obtained for a predetermined reference gasoline, that is, theheaviest gasoline A2 (which rarely evaporates) and the lightest gasolineNo. 7 (which easily evaporates) in the present example. Then, these dataare stored in the computer 72 constituting the identification controlportion.

Based on the calibration curve data, a proportional calculation iscarried out in the computer 72 and the type of the gasoline isidentified with the voltage output difference V0 obtained for theidentified gasoline.

More specifically, as shown in FIG. 11, a liquid type voltage outputVout for the voltage output difference V0 at a measuring temperature Tof the identified gasoline is correlated with an output voltage for avoltage output difference at a measuring temperature for a predeterminedthreshold reference gasoline (the gasoline A2 and the gasoline No. 7 inthe present example) and is thus corrected.

In other words, as shown in FIG. 11(A), a voltage output differenceV0−A2 of the gasoline A2, a voltage output difference V0-7 of thegasoline No. 7 and a voltage output difference V0-S of the identifiedgasoline are obtained at the temperature T based on the calibrationcurve data.

As shown in FIG. 11(B), the liquid type voltage output Vout of theidentified gasoline is obtainedby setting the liquid type output of thethreshold reference gasoline in this case to have a predeterminedvoltage, that is, by setting the liquid type output of the gasoline A2to be 3.5V and the liquid type output of the gasoline No. 7 to be 0.5Vin the present example. Thus, a correlation with the characteristics ofthe gasoline can be acquired.

The liquid type voltage output Vout of the identified gasoline iscompared with data previously stored in the computer 72 based on thecalibration curve data. Consequently, it is possible to identify theliquid type of the gasoline accurately and rapidly (instantaneously).

The method for identifying the liquid type of a gasoline described aboveutilizes a natural convection and a principle in which the kineticviscosity of the gasoline and the sensor output have a correlation.

In such a method for identifying the liquid type of a gasoline,moreover, it is apparent that a greater correlation is obtained withdistillation characteristics T30 to T70 of the gasoline shown in FIG.15, which is desirable.

In the case in which the alcohol is contained in the gasoline in theidentification of the liquid type of the gasoline as described above,liquid type identification data are influenced. Consequently, it is hardto identify the liquid type accurately and rapidly.

For this reason, in the present invention, the concentration of thealcohol contained in the gasoline is detected in the following manner.

More specifically, in a state in which the gasoline flowing into thefirst passage 14 through the gasoline inlet 18 then stays temporarily inthe alcohol content detecting chamber 56. In this state, if the alcoholis contained in the gasoline, the concentration of the alcohol contentis detected by an alcohol concentration detecting sensor 58 and thegasoline is then discharged from the alcohol content detecting chamber56 through a gasoline discharge port 54 of the second passage 16.

In the alcohol concentration detecting sensor 58, a difference in anelectrostatic capacitance is utilized depending on a difference betweenthe specific inductive capacity of alcohol contained in the gasoline andthe specific inductive capacity of the gasoline based on the followingEquation 2.C _(s)=ε₀(S/D) (ε ra(α/100)+ε rb(1−α/100)).  Equation 2

Herein, S represents an opposed area of an electrode, D represents adistance between the electrodes, ε₀ represents a specific inductivecapacity of a vacuum (8.854 E−12F/m), ε ra represents a specificinductive capacity of alcohol, ε rb represents a specific inductivecapacity of a gasoline, and α represents an alcohol concentration (%).

More specifically, as shown in a graph of FIG. 12 which represents arelationship between an alcohol concentration and an electrostaticcapacitance, the alcohol concentration and the electrostatic capacitancehave a correlation, and the alcohol concentration is detected byutilizing the correlation.

FIG. 12 shows an example in which ethanol is used for the alcohol and agasoline is used for the gasoline.

Moreover, the alcohol concentration detecting device 10 according to thepresent invention which uses the alcohol concentration detecting sensor58 comprises a detecting control portion 76 having a structure shown ina diagram of FIG. 13 illustrating the schematic structure of a circuit.

As shown in FIG. 13, in the detecting control portion 76, one of theelectrodes of the alcohol concentration detecting sensor 58 is groundedG1 and the other electrode of the alcohol concentration detecting sensor58 branches to be connected to the positive and negative inputs ofamplifiers (operational amplifiers) 78 and 80.

Moreover, resistors R1 to R3 are connected to a negative 82 a of a powersupply 82, and furthermore, the negative input of the amplifier 78 isconnected between R1 and R2 and the positive input of the amplifier 80is connected between R2 and R3, and an end of R3 is grounded G2.

The outputs of the amplifiers 78 and 80 are connected to S and R inputsof a flip-flop circuit 84, respectively. The output of the flip-flopcircuit 84 is input to the frequency counter of a computer 86.

Furthermore, the wiring of one of the electrodes of the alcoholconcentration detecting sensor 58 branches and is connected to apositive 82 b of the power supply 82 through resistors RA and RB. Atransistor 88 is connected between the resistors RA and RB, and theoutput of the transistor is connected between the output of theflip-flop circuit 84 and the computer 86. G3 denotes a ground of thetransistor 88.

In the detecting control portion 76 having such a structure, asquare-wave voltage shown in FIGS. 13 and 14 is applied at 90 in FIG.13.

As is expressed in the following Equation 3, consequently, arelationship between an oscillation frequency f and an electrostaticcapacitance C₅ is obtained.1/T=f=RA/(RA+2RB)·1/Cs (Hz)  Equation 3

In this case, it is possible to determine an amplitude T by properlysetting a duty ratio RA/(RA+2 RB). In the present example, 1.44 wasemployed for the duty ratio.

From such a relationship, a correlation is taken based on the graph ofFIG. 12. As shown in a graph of FIG. 15 representing a relationshipbetween an alcohol concentration and an oscillation frequency,consequently, it is apparent that the alcohol concentration and theoscillation frequency have a correlation. Thus, it is possible to detectthe alcohol concentration.

The data in FIGS. 12 and 15 are previously stored in the storage portionof the computer and are compared with data obtained in the detectingcontrol portion 76 so that the alcohol concentration can be detected.

Based on the alcohol concentration detected by the alcohol concentrationdetecting device, the liquid type identification data in theidentification control portion are corrected on the basis of alcoholconcentration data which are prestored in the identification controlportion so that the liquid type is identified.

As is apparent from the Equation 2, in order to obtain the excellentresult of a measurement, it is preferable that the distance D betweenelectrodes should be reduced to increase the electrostatic capacitanceC_(s).

In the alcohol concentration detecting device 10 according to thepresent invention, therefore, the alcohol concentration detecting sensor58 is constituted in the following manner.

More specifically, FIG. 16 is a schematic perspective view showing anexample of the alcohol concentration detecting sensor 58 of the alcoholconcentration detecting device according to the present invention, FIG.17 is a schematic top view showing an electrode wiring pattern in FIG.16, FIG. 18 is an enlarged view showing a B portion in FIG. 17, and FIG.19 is a partially enlarged sectional view taken along a C—C line in FIG.16.

As shown in FIGS. 16 to 19, the alcohol concentration detecting sensor58 includes an alcohol concentration detecting sensor body 11constituted by a base material resin film 92, electrode wiring patterns94 and 96 formed on the base material resin film 92, and an insulatingresin 98 covering the surfaces of the electrode wiring patterns 94 and96. The alcohol concentration detecting sensor body 11 is stuck to asubstrate 13 with an adhesive which is not shown.

In this case, it is preferable that a polyimide resin film should beused for the base material resin film 92 in consideration of aflexibility, a chemical resistance and the like. As shown in FIG. 19,moreover, a thickness T1 is not particularly restricted. In the presentexample, a thickness of 40 μm was used for T1.

Furthermore, the electrode wiring pattern 94 on a positive side and theelectrode wiring pattern 96 on a ground (a negative side) have suchshapes that positive electrodes 94 a and negative electrodes 96 a whichare comb-toothed are alternately intricate, respectively. In FIG. 16, 94b and 96 b denote a fetch electrode portion, respectively.

By such a structure, a plurality of electrodes having a very smalldistance therebetween can be provided to be compact as a whole.

In this case, while a length L1 of the electrode is not particularlyrestricted as shown in FIG. 17, it is desirably set to be 100 μm or morein consideration of the electrostatic capacitance of the liquid to beinspected. In the present example, a length of 10 mm was employed forL1.

While a width W1 of each of the positive electrode 94 a and the negativeelectrode 96 a is not particularly restricted as shown in FIG. 18,moreover, it is preferably set to be 1 to 50 μm, and more preferably, 5to 15 μm in consideration of the electrostatic capacitance. Furthermore,a width W2 between the positive electrode 94 a and the negativeelectrode 96 a is not particularly restricted but is preferably set tobe 1 to 50 μm, and more preferably 5 to 15 μm in consideration of theelectrostatic capacitance. In the present example, W1/W2=30/30 μm wasemployed.

While the numbers of the positive electrodes 94 a and the negativeelectrodes 96 a which are comb-toothed are not particularly restricted,moreover, they are preferably equal to or larger than 1, and morepreferably, are more increased in consideration of the electrostaticcapacitance. In the present example, 64 pairs (128 in total)comb-toothed electrodes were used.

While a thickness T2 of each of the electrode wiring patterns 94 and 96is not particularly restricted as shown in FIG. 19, furthermore, it ispreferably set to be 1 to 50 μm, and more preferably, 5 to 15 μm inconsideration of the electrostatic capacitance. In the present example,T2 of 10 μm was employed.

In this case, the electrode wiring patterns 94 and 96 are obtained byselectively etching a conductive metallic foil laminated on one of thesurfaces of the base material resin film 92 to form wiring patternstaking predetermined shapes as will be described below.

Although such a conductive metallic foil is not particularly restricted,a copper foil is preferable. Consequently, a high conductivity can beobtained and the concentration of alcohol can be detected veryaccurately and rapidly.

Furthermore, it is preferable that the insulating resin 98 should beformed by at least one insulating resin selected from an urethane resin,a polyimide resin and an epoxy type resin.

By using such a resin as the insulating resin 98, it is possible toeasily apply the insulating resin onto the surfaces of the electrodewiring patterns 94 and 96.

While a thickness T3 of the insulating resin 98 is not particularlyrestricted as shown in FIG. 19, moreover, it is desirable that thethickness T3 should be smaller with an insulating property and astrength maintained in consideration of the fact that the electrostaticcapacitance of the insulating resin itself does not influence sensing.In the present example, T3 of 18 μm was employed.

While the material of the substrate 13 is not particularly restricted,furthermore, it is possible to employ a glass substrate, a ceramicssubstrate, a resin substrate or the like in consideration of aninsulating property. Although the thickness is not particularlyrestricted, it is preferably set to be 100 to 1000 μm, and morepreferably, 250 to 600 μm in consideration of an insulating property, astrength and the like. In the present example, a thickness of 360 μm wasemployed.

By such a structure, it is possible to reduce the distance between theelectrodes by using the electrode wiring patterns 94 and 96 formed onthe base material resin film 92. As is apparent from the Equation 2,therefore, the electrostatic capacitance C_(s) can be increased so thatthe excellent result of the measurement can be obtained.

In addition, the alcohol concentration detecting sensor 58 isconstituted by the base material resin film 92, the electrode wiringpatterns 94 and 96 formed on the base material resin film 92, and theinsulating resin 98 covering the surfaces of the electrode wiringpatterns 94 and 96. For this reason, the sensor itself is flexible,thin, very small and compact, and can be installed everywhere so thatthe degree of freedom of a design can be enhanced.

Since the surfaces of the electrode wiring patterns 94 and 96 arecovered with the insulating resin 98, furthermore, an insulation betweenthe electrodes can be enhanced and is not influenced by a moisture, andshielding can be carried out so as not to be influenced by anelectromagnetic wave generated from a body of a car or the like.Furthermore, the alcohol concentration can be measured accurately.

Moreover, the electrode does not directly come in contact with thegasoline. Therefore, a defective operation can be prevented from beingcaused by a deterioration with the passage of time, foreign matters inthe gasoline or the like. Thus, it is possible to detect the alcoholconcentration accurately and rapidly.

With reference to FIG. 20, description will be given to a method formanufacturing the alcohol concentration detecting sensor of the alcoholconcentration detecting device according to the present invention whichhas such a structure.

As shown in FIG. 20(A), first of all, a conductive metallic foil 15 isstuck to one of the surfaces of the base material resin film 92 bycontact bonding with an adhesive which is not shown (a conductivemetallic foil sticking step).

As shown in FIG. 20(B), then, a photoresist 17 is applied onto the wholeupper surface of the conductive metallic foil 15 by using a spin coater(3000 rpm), for example (a photoresist applying step).

As shown in FIG. 20(C), next, the photoresist 17 is exposed byultraviolet rays to take a desirable electrode wiring pattern shape byusing a photoresist mask 19 taking a shape corresponding to apredetermined wiring pattern, for example (a photoresist exposing step).

As shown in FIG. 20(D), then, a photoresist portion 17 a thus exposed isdissolved and removed with a developing solution (a photoresistdissolving and removing step).

As shown in FIG. 20(E), thereafter, a conductive metallic foil portion15 a which is not covered with the photoresist 17 b is subjected to anetching treatment with an etchant such as acid or alkali and is thusremoved to obtain a predetermined wiring pattern shape 15 b (an etchingstep).

As shown in FIG. 20(F), subsequently, the photoresist 17 b is dissolvedand removed with a dissolving and removing solution such as acetone (aphotoresist dissolving and removing step).

As shown in FIG. 20(G), next, the insulating resin 98 is applied ontothe surface from which the photoresist is removed by screen printing,for example, and the alcohol concentration detecting sensor body 11 isthus obtained (an insulating resin applying step).

As shown in FIG. 20(H) and FIG. 19, finally, the alcohol concentrationdetecting sensor body 11 obtained at the insulating resin applying stepis stuck onto the substrate 13 (a substrate sticking step).

According to the method for manufacturing the alcohol concentrationdetecting sensor 58 of the alcohol concentration detecting device inaccordance with the present invention, it is possible to obtain anelectrode wiring pattern in which a distance between electrodes is verysmall, for example, approximately 5 μm to 50 μm. Therefore, it ispossible to easily supply, on a large scale, an alcohol concentrationdetecting sensor in which the electrostatic capacitance C_(s) can beincreased and the excellent result of the measurement can be obtained,and furthermore, the sensor itself is thin, very small and compact, andcan be installed everywhere so that the degree of freedom of a designcan be enhanced.

FIG. 21 is a schematic perspective view showing another example of thealcohol concentration detecting sensor 58 of the alcohol concentrationdetecting device according to the present invention, FIG. 22 is aschematic top view showing an electrode wiring pattern in FIG. 21, FIG.23 is an enlarged view showing a B portion in FIG. 22, and FIG. 24 is apartially enlarged sectional view taken along a C—C line in FIG. 21.

The alcohol concentration detecting sensor 58 according to the presentexample has basically the same structure as that of the alcoholconcentration detecting sensor 58 according to the example shown inFIGS. 16 to 19. Therefore, the same components are indicated as thereference numerals having a dash and detailed description thereof willbe omitted.

The alcohol concentration detecting sensor 58 according to the presentexample comprises a substrate 92′, electrode wiring patterns 94′ and 96′formed on the substrate 92′, and an insulating coat 98′ covering thesurfaces of the electrode wiring patterns 94′ and 96′.

In this case, the electrode wiring patterns 94′ and 96′ are obtained byselectively etching a conductive metallic thin film formed on one of thesurfaces of the substrate 92′ through sputtering to provide a wiringpattern taking a predetermined shape.

While such a conductive metallic thin film is not particularlyrestricted, nickel, copper, platinum or the like can be used and theplatinum is desirably used in consideration of an oxidation resistanceor the like.

While a thickness T2 of each of the electrode wiring patterns 94′ and96′ is not particularly restricted as shown in FIG. 24, moreover, it ispreferably set to be 0.1 to 1.0 μm, and more preferably, 0.1 to 0.5 μmin consideration of an efficiency in the formation of a thin film by thesputtering.

While the material of the substrate 92′ is not particularly restricted,furthermore, a glass substrate, a ceramics substrate such as alumina, aresin substrate or the like can be employed in consideration of the factthat the material is not influenced by sputtering or the like. While thethickness is not particularly restricted, it is preferably set to be 100to 1000 μm, and more preferably, 250 to 600 μm in consideration of aninsulating property, a strength or the like. In the present example, athickness of 360 μm was used. A size depends on the size of a sputteringdevice, and desirably, 2-inch and 4-inch square sizes can be used.

While the insulating coat 98′ is not particularly restricted, moreover,it is preferably constituted by at least one minute insulating coatselected from SiO₂, Al₂O₃ and the like.

In this case, it is preferable that the insulating coat 98′ should beformed by chemical vapor deposition (CVD).

By such a structure, it is possible to obtain, by the chemical vapordeposition (CVD), a very minute and thin insulating coat which is notinfluenced by a liquid to be inspected such as a gasoline or alcohol,for example, SiO₂, Al₂O₃ or the like, and the sensor itself can be thin,very small and compact.

While a thickness T3 of the insulating coat 98′ is not particularlyrestricted as shown in FIG. 24, moreover, it is desirable that thethickness T3 should be smaller with an insulating property and astrength maintained in consideration of the fact that the electrostaticcapacitance of the insulating coat itself such as an insulatingproperty, a strength and the like does not influence sensing. In thepresent example, T3 of 1 μm was employed.

By such a structure, it is possible to reduce the distance between theelectrodes by using the electrode wiring patterns 94′ and 96′ formed onthe substrate 92′. As is apparent from the Equation 2, therefore, theelectrostatic capacitance C_(s) can be increased and the excellentresult of the measurement can be obtained.

In addition, the alcohol concentration detecting sensor is constitutedby the substrate 92′, the electrode wiring patterns 94′ and 96′ formedon the substrate 92′, and the insulating coat 98′ covering the surfacesof the electrode wiring patterns 94′ and 96′. For this reason, thesensor itself is thin, very small and compact, and can be installedeverywhere so that the degree of freedom of a design can be enhanced.

Since the surfaces of the electrode wiring patterns are covered with theinsulating coat 98′, furthermore, an insulation between the electrodescan be enhanced and is not influenced by a moisture, and shielding canbe carried out so as not to be influenced by an electromagnetic wavegenerated from a body of a car or the like, and furthermore, the alcoholconcentration can be measured accurately.

Moreover, the electrode does not directly come in contact with thegasoline. Therefore, a defective operation can be prevented from beingcaused by a deterioration with the passage of time, foreign matters inthe gasoline or the like. Thus, it is possible to detect the alcoholconcentration accurately and rapidly.

In addition, the substrate 92′ is provided. Therefore, it is easy toassemble and attach the alcohol concentration detecting sensor into theapparatus.

Furthermore, it is possible to obtain an electrode wiring pattern havinga thickness of 0.1 to 5 μm by sputtering at a very small distancebetween the electrodes, for example, within a range of approximately 5μm to 50 μm by the sputtering. Therefore, the electrostatic capacitanceC_(s) can be increased so that the excellent result of the measurementcan be obtained.

With reference to FIG. 25, description will be given to a method formanufacturing the alcohol concentration detecting sensor of the alcoholconcentration detecting device according to the present invention whichhas such a structure.

As shown in FIG. 25(A), first of all, a conductive metallic thin film15′ is formed on one of the surfaces of the substrate 92′ by thesputtering (a conductive metallic thin film forming step).

As shown in FIG. 25(B), then, a photoresist 17 is applied onto the wholeupper surface of the conductive metallic thin film 15′ by using a spincoater (3000 rpm), for example (a photoresist applying step).

As shown in FIG. 25(C), next, the photoresist 17 is exposed byultraviolet rays to take a desirable electrode wiring pattern shape byusing a photoresist mask 19 taking a shape corresponding to apredetermined wiring pattern, for example (a photoresist exposing step).

As shown in FIG. 25(D), then, a photoresist portion 17 a thus exposed isdissolved and removed with a developing solution (a photoresistdissolving and removing step).

As shown in FIG. 25(E), thereafter, a conductive metallic thin filmportion 15 a which is not covered with the photoresist 17 b is subjectedto a dry etching treatment by using an argon ion or the like, forexample, and is thus removed to obtain a predetermined wiring patternshape 15 b (an etching step).

As shown in FIG. 25(F), subsequently, the photoresist 17 b is dissolvedand removed with a dissolving and removing solution such as acetone (aphotoresist dissolving and removing step).

As shown in FIG. 25(G), finally, the insulating coat 98′ is formed, bythe chemical vapor deposition (CVD), on the surface from which thephotoresist is removed (an insulating coat forming step).

By such a structure, it is possible to obtain an electrode wiringpattern having a thickness of 0.1 to 5 μm by the sputtering at a verysmall distance between the electrodes, for example, within a range ofapproximately 5 μm to 50 μm. Therefore, it is possible to easily supply,on a large scale, an alcohol concentration detecting sensor in which theelectrostatic capacitance CS can be increased so that the excellentresult of the measurement can be obtained, and furthermore, the sensoritself is thin, very small and compact, and can be installed everywhereso that the degree of freedom of a design can be increased.

FIG. 26 is the same schematic diagram as FIG. 28, illustrating anexample in which the apparatus 10 for identifying the liquid type of agasoline having such a structure is applied to a car system.

The same components as those in FIG. 28 have the same reference numeralsand detailed description thereof will be omitted.

In a car system 100, the apparatus 10 for identifying the liquid type ofa gasoline is provided in a gasoline tank 108 or on the upstream side ofa gasoline pump 110.

The apparatus 10 for identifying the liquid type of a gasolineidentifies the liquid type of a gasoline in the gasoline tank 108 or onthe upstream or downstream side of the gasoline pump 110 (the case ofthe upstream side will be described in the present example forconvenience of explanation) and regulates an ignition timing by anignition timing control device 122 under the control of a control device120 depending on the type of the gasoline.

More specifically, in the case in which the light gasoline No. 7 (whicheasily evaporates) is identified, for example, the ignition timing iscontrolled to be quickened. To the contrary, in the case in which theheavy gasoline A2 (which rarely evaporates) is identified, the ignitiontiming is controlled to be delayed.

Consequently, it is also possible to reduce the amount of HC in anexhaust gas and to enhance a mileage without decreasing a torque,particularly, at time of engine starting in which an engine and acatalytic device do not warm up.

FIG. 27 is the same schematic diagram as FIG. 28, illustrating anexample in which the apparatus 10 for identifying the liquid type of agasoline having such a structure is applied to a car system.

The same components as those in FIG. 28 have the same reference numeralsand detailed description thereof will be omitted.

In a car system 100, the apparatus 10 for identifying the liquid type ofa gasoline is provided in a gasoline tank 108 or on the upstream side ofa gasoline pump 110.

The apparatus 10 for identifying the liquid type of a gasolineidentifies the liquid type of a gasoline in the gasoline tank 108 or onthe upstream or downstream side of the gasoline pump 110 (the case ofthe upstream side will be described in the present example forconvenience of explanation) and regulates the compressibility of thegasoline by a gasoline compression control device 124 under the controlof a control device 120 depending on the type of the gasoline.

More specifically, in the case in which the light gasoline No. 7 (whicheasily evaporates) is identified, for example, the compressibility iscontrolled to be reduced. To the contrary, in the case in which theheavy gasoline A2 (which rarely evaporates) is identified, thecompressibility is controlled to be increased.

Consequently, it is also possible to reduce the amount of HC in anexhaust gas and to enhance a mileage without decreasing a torque,particularly, at time of engine starting in which an engine and acatalytic device do not warm up.

While the preferred examples of the present invention have beendescribed above, the present invention is not restricted thereto butvarious changes can be made without departing from the objects of thepresent invention, for example, a pulse voltage P, the number ofsampling operations and the like can be changed properly.

According to the present invention, it is sufficient that a pulsevoltage is simply applied for a predetermined time. Consequently, it ispossible to identify the type of a gasoline accurately and rapidlythrough heating for a short time without carrying out the heating tosuch a temperature as to ignite the gasoline.

More specifically, there are utilized the correlation of the kineticviscosity of the gasoline with a sensor output, a natural convection,and furthermore, an applied voltage having one pulse. Therefore, it ispossible to identify the type of the gasoline accurately and rapidly.

According to the present invention, moreover, it is possible toaccurately obtain a voltage output difference V0 based on the averagevalue of sampling at a predetermined number of times for the appliedvoltage having one pulse. Consequently, it is possible to identify thetype of the gasoline accurately and rapidly.

According to the present invention, furthermore, the type of thegasoline is identified with the voltage output difference V0 obtainedfor the identified gasoline based on calibration curve data to be thecorrelation of a voltage output difference with a temperature for apredetermined reference gasoline which is prestored. Therefore, it ispossible to identify the type of the gasoline more accurately andrapidly.

According to the present invention, moreover, a liquid type voltageoutput Vout for the voltage output difference V0 at the measuringtemperature of the identified gasoline is correlated with the outputvoltage for the voltage output difference at the measuring temperaturefor a predetermined threshold reference gasoline and is thus corrected.Consequently, it is possible to eliminate the influence of thetemperature on the voltage output difference V0, thereby giving thecorrelation of the liquid type voltage output Vout with thecharacteristics of the gasoline more accurately. Thus, it is possible toidentify the type of the gasoline further accurately and rapidly.

According to the present invention, furthermore, a mechanism portion forcarrying out a mechanical operation is not present. Therefore, adefective operation can be prevented from being caused by adeterioration with the passage of time, foreign matters in the gasolineor the like. Thus, it is possible to identify the liquid type of thegasoline accurately and rapidly.

In addition, a sensor portion can be constituted to be very small-sized.Consequently, it is possible to identify the liquid type of the gasolineaccurately with a very excellent thermal responsiveness.

According to the present invention, moreover, the heater of the liquidtype identifying sensor heater, the identifying liquid temperaturesensor and the liquid temperature sensor do not directly come in contactwith the identified gasoline. Therefore, a defective operation can beprevented from being caused by a deterioration with the passage of time,foreign matters in the gasoline or the like. Thus, it is possible toidentify the liquid type of the gasoline accurately and rapidly.

In addition, according to the present invention, based on the alcoholconcentration detected by the alcohol concentration detecting device,the liquid type identification data in the identification controlportion are corrected on the basis of alcohol concentration data whichare prestored in the identification control portion so that the liquidtype is identified. Therefore, it is possible to identify the type ofthe gasoline more accurately and rapidly.

According to the present invention, moreover, it is possible to reduce adistance between the electrodes by using an electrode wiring patternformed on a base material resin film. As is apparent from the Equation2, therefore, an electrostatic capacitance C_(s) can be increased sothat the excellent result of the measurement can be obtained.

In addition, the alcohol concentration detecting sensor is constitutedby the base material resin film, the electrode wiring pattern formed onthe base material resin film, and the insulating resin covering thesurface of the electrode wiring pattern. Therefore, a sensor itself isflexible, thin, very small and compact, and can be installed everywhereso that the degree of freedom of a design can be increased.

Furthermore, the surface of the electrode wiring pattern is covered withthe insulating resin. Therefore, an insulation between the electrodes isexcellent and is not influenced by a moisture, and shielding can becarried out in order to prevent the influence of an electromagnetic wavegenerated from the body of a car or the like, and furthermore, anaccurate measurement for the alcohol concentration can be executed.

According to the present invention, moreover, it is possible to obtainan electrode wiring pattern having a very small distance between theelectrodes, for example, within a range of approximately 5 μm to 50 μmby etching. Therefore, the electrostatic capacitance C_(s) can beincreased so that the excellent result of the measurement can beobtained.

According to the present invention, furthermore, it is possible toreduce a distance between the electrodes by using the electrode wiringpattern formed on the substrate. As is apparent from the Equation 2described above, therefore, the electrostatic capacitance C_(s) can beincreased so that the excellent result of the measurement can beobtained.

In addition, the alcohol concentration detecting sensor is constitutedby the substrate, the electrode wiring pattern formed on the substrate,and the insulating coat covering the surface of the electrode wiringpattern. Therefore, the sensor itself is thin, very small and compact,and can be installed everywhere so that the degree of freedom of adesign can be increased.

Moreover, the surface of the electrode wiring pattern is covered withthe insulating coat. Therefore, an insulation between the electrodes isexcellent and is not influenced by a moisture, and shielding can becarried out in order to prevent the influence of an electromagnetic wavegenerated from the body of a car or the like, and furthermore, anaccurate measurement for the alcohol concentration can be executed.

According to the present invention, furthermore, it is possible toobtain an electrode wiring pattern having a thickness of 0.1 to 5 μm bysputtering at a very small distance between the electrodes, for example,within a range of approximately 5 μm to 50 μm by the sputtering.Therefore, the electrostatic capacitance C_(s) can be increased so thatthe excellent result of the measurement can be obtained.

According to the present invention, moreover, it is possible to obtain,by chemical vapor deposition (CVD), a very minute and thin insulatingcoat which is not influenced by a gasoline such as a gasoline oralcohol, for example, SiO₂, Al₂O₃ or the like. Thus, the sensor itselfcan be thin, very small and compact.

Furthermore, the electrode does not directly come in contact with thegasoline. Therefore, a defective operation can be prevented from beingcaused by a deterioration with the passage of time, foreign matters inthe gasoline or the like. Thus, it is possible to detect the alcoholconcentration accurately and rapidly.

In addition, the substrate is provided. Therefore, it is easy toassemble and attach the alcohol concentration detecting sensor into theapparatus.

According to the present invention, moreover, the positive and negativeelectrodes which are comb-toothed are formed to be alternatelyintricate. Therefore, the electrodes having a very small distancetherebetween can be provided to be compact as a whole.

Accordingly, it is possible to obtain an electrode wiring pattern havinga very small distance between the electrodes, for example, within arange of approximately 5 μm to 50 μm by etching and sputtering,respectively. Therefore, the electrostatic capacitance Cs can beincreased so that the excellent result of the measurement can beobtained.

According to the present invention, furthermore, the alcoholconcentration in the gasoline can be detected accurately and rapidly,and it is possible to control a torque to be constant by excessivelyadding a gasoline corresponding to the amount of addition of alcohol,for example, ethanol as an antiknocking agent.

According to the present invention, furthermore, it is possible toidentify the type of the gasoline in a car accurately and rapidly and toregulate an ignition timing based on the result of the identification ofthe type of the gasoline. Consequently, it is possible to obtain aproper ignition timing depending on the type of the gasoline.

According to the present invention, furthermore, it is possible toidentify the type of the gasoline in a car accurately and rapidly and toregulate the compressibility of the gasoline based on the result of theidentification of the type of the gasoline. Consequently, it is possibleto obtain a proper compressibility of the gasoline depending on the typeof the gasoline.

Therefore, it is also possible to reduce the amount of HC in an exhaustgas and to enhance a mileage without decreasing a torque, particularly,at time of engine starting in which an engine and a catalytic device donot warm up. Thus, the present invention can produce various remarkableand peculiar functions and effects, which is very excellent.

1. An apparatus for identifying a liquid type of a gasoline, comprising: a gasoline liquid type identifying chamber for causing an identified gasoline introduced into a liquid type identifying apparatus body to stay temporarily; a liquid type identifying sensor heater provided in the gasoline liquid type identifying chamber; and a liquid temperature sensor provided in the gasoline liquid type identifying chamber apart from the liquid type identifying sensor heater at a constant interval; the liquid type identifying sensor heater including a heater and an identifying liquid temperature sensor provided in the vicinity of the heater, the apparatus further comprising an identification control portion for applying a pulse voltage to the liquid type identifying sensor heater for a predetermined time, heating the identified gasoline staying temporarily in the gasoline liquid type identifying chamber by the heater and identifying the liquid type with a voltage output difference V0 corresponding to a temperature difference between an initial temperature and a peak temperature in the identifying liquid temperature sensor, and an alcohol content detecting chamber, the alcohol content detecting chamber being provided with an alcohol concentration detecting device in which an alcohol concentration in the gasoline is detected by introducing a gasoline between electrodes of an alcohol concentration detecting sensor, and by measuring a change in a specific inductive capacity of the gasoline between the electrodes with an oscillation frequency, and based on the alcohol concentration detected by the alcohol concentration detecting device, liquid type identification data in the identification control portion being corrected on the basis of alcohol concentration data which are prestored in the identification control portion, thereby identifying a liquid type.
 2. The apparatus for identifying a liquid type of a gasoline according to claim 1, wherein the voltage output difference V0 is equal to a voltage difference between an average initial voltage V1 obtained by sampling an initial voltage before application of the pulse voltage at a predetermined number of times and an average peak voltage V2 obtained by sampling a peak voltage after the application of the pulse voltage at a predetermined number of times, that is, V0=V2−V1.
 3. The apparatus for identifying a liquid type of a gasoline according to claim 1, wherein in accordance with calibration curve data to be a correlation of a voltage output difference with a temperature for a predetermined reference gasoline prestored in the identification control portion, the identification control portion is constituted to identify a type of a gasoline with the voltage output difference V0 obtained for the identified gasoline.
 4. The apparatus for identifying a liquid type of a gasoline according to claim 1, wherein the identification control portion is constituted to correlate a liquid type voltage output Vout for the voltage output difference V0 at a measuring temperature of the identified gasoline with an output voltage for a voltage output difference at a measuring temperature for a predetermined threshold reference gasoline and to thus carry out a correction.
 5. The apparatus for identifying a liquid type of a gasoline according to claim 1, wherein the liquid type identifying sensor heater is a laminated liquid type identifying sensor heater in which a heater and an identifying liquid temperature sensor are laminated through an insulating layer.
 6. The apparatus for identifying a liquid type of a gasoline according to claim 1, wherein the heater and the identifying liquid temperature sensor in the liquid type identifying sensor heater are constituted to come in contact with the identified gasoline through a metallic fin, respectively.
 7. The apparatus for identifying a liquid type of a gasoline according to claim 1, wherein the liquid temperature sensor is constituted to come in contact with the identified gasoline through the metallic fin.
 8. The apparatus for identifying a liquid type of a gasoline according to claim 1, wherein the alcohol concentration detecting sensor comprises an alcohol concentration detecting sensor body including a base material resin film, an electrode wiring pattern formed on the base material resin film, and an insulating resin covering a surface of the electrode wiring pattern.
 9. The apparatus for identifying a liquid type of a gasoline according to claim 8, wherein the alcohol concentration detecting sensor body is stuck onto a substrate.
 10. The apparatus for identifying a liquid type of a gasoline according to claim 8, wherein the electrode wiring pattern is obtained by selectively etching a conductive metallic foil laminated on one of surfaces of the base material resin film, thereby forming a wiring pattern taking a predetermined shape.
 11. The apparatus for identifying a liquid type of a gasoline according to claim 1, wherein the alcohol concentration detecting sensor comprises a substrate, an electrode wiring pattern formed on the substrate, and an insulating coat covering a surface of the electrode wiring pattern.
 12. The apparatus for identifying a liquid type of a gasoline according to claim 11, wherein the electrode wiring pattern is obtained by selectively etching a conductive metallic thin film formed on one of surfaces of the substrate by sputtering, thereby forming a wiring pattern taking a predetermined shape.
 13. The apparatus for identifying a liquid type of a gasoline according to claim 11, wherein the insulating coat is formed by chemical vapor deposition (CVD).
 14. The apparatus for identifying a liquid type of a gasoline according to claim 8, wherein the electrode wiring pattern has such a shape that positive and negative electrodes which are comb-toothed are alternately intricate.
 15. An apparatus for identifying a liquid type of a gasoline of a car, wherein the apparatus for identifying a liquid type of a gasoline according to claim 1 is provided in a gasoline tank or on an upstream side or a downstream side of a gasoline pump.
 16. An apparatus for reducing an exhaust gas of a car, comprising: the apparatus for identifying a liquid type of a gasoline according to claim 1 which is provided in a gasoline tank or on an upstream side or a downstream side of a gasoline pump; and an ignition timing control device for regulating an ignition timing based on the type of the gasoline which is identified by the apparatus for identifying a liquid type of a gasoline.
 17. An apparatus for reducing an exhaust gas of a car, comprising: the apparatus for identifying a liquid type of a gasoline according to claim 1 which is provided in a gasoline tank or on an upstream side or a downstream side of a gasoline pump; and a gasoline compression control device for regulating a compressibility of the gasoline based on the type of the gasoline which is identified by the apparatus for identifying a liquid type of a gasoline.
 18. A method for identifying a liquid type of a gasoline, comprising the steps of: applying a pulse voltage for a predetermined time to a liquid type identifying sensor heater including a heater and an identifying liquid temperature sensor provided in the vicinity of the heater; heating an identified gasoline by the heater; and identifying the liquid type with a voltage output difference V0 corresponding to a temperature difference between an initial temperature and a peak temperature in the identifying liquid temperature sensor; introducing a gasoline between electrodes of an alcohol concentration detecting sensor, and measuring a change in a specific inductive capacity of the gasoline between the electrodes with an oscillation frequency thereby detecting an alcohol concentration in the gasoline; and wherein based on the alcohol concentration detected by the alcohol concentration detecting device, correcting liquid type identification data in the identification control portion on the basis of alcohol concentration data which are prestored in the identification control portion, thereby identifying a liquid type.
 19. The method for identifying a liquid type of a gasoline according to claim 18, wherein the voltage output difference V0 is equal to a voltage difference between an average initial voltage V1 obtained by sampling an initial voltage before application of the pulse voltage at a predetermined number of times and an average peak voltage V2 obtained by sampling a peak voltage after the application of the pulse voltage at a predetermined number of times, that is, V0=V2−V1.
 20. The method for identifying a liquid type of a gasoline according to claim 18, wherein in accordance with calibration curve data to be a correlation of a voltage output difference with a temperature for a predetermined reference gasoline which is prestored, a type of a gasoline is identified with the voltage output difference V0 obtained for the identified gasoline.
 21. The method for identifying a liquid type of a gasoline according to claim 18, wherein a liquid type voltage output Vout for the voltage output difference V0 at a measuring temperature of the identified gasoline is correlated with an output voltage for a voltage output difference at a measuring temperature for a predetermined threshold reference gasoline and is thus corrected.
 22. The method for identifying a liquid type of a gasoline according to claim 18, wherein the liquid type identifying sensor heater is a laminated liquid type identifying sensor heater in which a heater and an identifying liquid temperature sensor are laminated through an insulating layer.
 23. The method for identifying a liquid type of a gasoline according to claim 18, wherein the heater and the identifying liquid temperature sensor in the liquid type identifying sensor heater are constituted to come in contact with the identified gasoline through a metallic fin, respectively.
 24. The method for identifying a liquid type of a gasoline according to claim 18, wherein the liquid temperature sensor is constituted to come in contact with the identified gasoline through the metallic fin.
 25. The method for identifying a liquid type of a gasoline according to claim 18, wherein the alcohol concentration detecting sensor comprises an alcohol concentration detecting sensor body including a base material resin film, an electrode wiring pattern formed on the base material resin film, and an insulating resin covering a surface of the electrode wiring pattern.
 26. The method for identifying a liquid type of a gasoline according to claim 25, wherein the alcohol concentration detecting sensor body is stuck onto a substrate.
 27. The method for identifying a liquid type of a gasoline according to claim 25, wherein the electrode wiring pattern is obtained by selectively etching a conductive metallic foil laminated on one of surfaces of the base material resin film, thereby forming a wiring pattern taking a predetermined shape.
 28. The method for identifying a liquid type of a gasoline according to claim 18, wherein the alcohol concentration detecting sensor comprises a substrate, an electrode wiring pattern formed on the substrate, and an insulating coat covering a surface of the electrode wiring pattern.
 29. The method for identifying a liquid type of a gasoline according to claim 28, wherein the electrode wiring pattern is obtained by selectively etching a conductive metallic thin film formed on one of surfaces of the substrate by sputtering, thereby forming a wiring pattern taking a predetermined shape.
 30. The method for identifying a liquid type of a gasoline according to claim 28, wherein the insulating coat is formed by chemical vapor deposition (CVD).
 31. The method for identifying a liquid type of a gasoline according to claim 25, wherein the electrode wiring pattern has such a shape that positive and negative electrodes which are comb-toothed are alternately intricate.
 32. A method for identifying a liquid type of a gasoline of a car, comprising the step of: identifying a type of a gasoline in a gasoline tank or on an upstream side or a downstream side of a gasoline pump by using the method for identifying a liquid type of a gasoline according to claim
 15. 33. A method for reducing an exhaust gas of a car, comprising the steps of: identifying a type of a gasoline in a gasoline tank or on an upstream side or a downstream side of a gasoline pump by using the method for identifying a liquid type of a gasoline according to claim 18; and regulating an ignition timing based on the type of the gasoline which is identified by the apparatus for identifying a liquid type of a gasoline.
 34. A method for reducing an exhaust gas of a car, comprising the steps of: identifying a type of a gasoline in a gasoline tank or on an upstream side or a downstream side of a gasoline pump by using the method for identifying a liquid type of a gasoline according to claim 18; and regulating a compressibility of the gasoline based on the type of the gasoline which is identified by the apparatus for identifying a liquid type of a gasoline. 